Sustainable Stimuli-Responsive Wound Dressing Made of Green Materials
Typ
Examensarbete för masterexamen
Program
Materials chemistry (MPMCN), MSc
Publicerad
2022
Författare
Hummerhielm, Robert
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
Non-healing chronic wound are wound that have a naturally high infection risk and
produce an excess of exudate. To better treat these wounds, having a wound dressing
that can absorb much of the exudate, keep the wound environment moist, and
administer antibiotics when the wound is infected would be ideal. Here, a wound
dressing that can absorb large amounts of exudate and locally administer drugs as
a response to high pH commonly seen in infected wounds was prepared. First a carboxymethyl
cellulose (CMC) aerogel scaffold was first prepared, using ethylene glycol
diglycidyl ether (EGDE) as a cross-linker. The scaffold was then impregnated via
diffusion or injection with naproxen-loaded pH-sensitive lignin nanoparticles (LNPs),
synthesized using an anti-solvent method. Scanning electron microscopy (SEM) was
used to investigate the morphology of the CMC gel as well as the shape and size
of the synthesized unloaded and naproxen-loaded LNPs. The LNPs efficiency as
drug-vehicles was investigated by loading the LNPs with naproxen and calculating
the loading capacity and encapsulation efficiency of naproxen. Fourier Transform
IR was used to investigate the cross-linking of CMC and EGDE and a tea bag test
was used investigate the swelling capacity of the CMC gel.
During the synthesis of the CMC gel, several parameters were varied. This resulted
in aerogels with different morphologies and properties. Depending on the synthesis
parameters, a swelling ratio between 28 and 623 g/g. A high swelling capacity was
obtained by adding low concentrations of CMC and EGDE. The lowest swelling
capacity was obtained by adding high EGDE concentrations and drying the gel via
freeze-drying and oven-drying.
Based on the SEM images of LNPs, unloaded and naproxen-loaded LNPs had a
desired spherical shape with an average size of 71.6 and 81 nm, respectively. The
size distribution was quite large for both LNPs between 31.5–127 nm for unloaded
and 26.5–140 nm. The loading capacity of naproxen was around 10% while the
encapsulation efficiency was around 48%.
Based on the SEM images of the impregnated aerogels, no LNPs could be found.
Either no LNPs were present in the sample taken or the LNPs have dissolved due
to high pH.
Beskrivning
Ämne/nyckelord
wound dressings , carboxymethyl cellulose , aerogel , lignin nanoparticles , drug-loading